LTE: What does mcch-Offset signify ?

Question

I know one MCCH channel is associated to one MBSFNArea Configuration and MBSFNAreaConfiguration carries the configuration associated to a particular MBSFNArea. I have no idea of use of SC-MCCH logical channel. Can a cell support both logical channels simultaneously ? If both can exist together in a cell then UE will choose which channel ? Can someone please share his/her thoughts over these queries ? Thanks in advance.

Answer 1

As far as I know, SIB2 and SIB13 carries MBMB related information.
SIB2 exactly tells about radio frames which are being used for a MBFSN area.
SIB13 carries information related to MCCH configuration. It informs about exact location of MCCH by using MCCH repetition period and MCCH offset period.
MCCH offset exactly tells about which radio frame will carry MCCH information within its repetition period.
There is another important information i.e. sf-AllocInfo-r9 which comes as part of MCCH config. This sf-AllocInfo-r9 tells about the exact subframe# which will carry MCCH. As we know, only 6 out of 10 subframes of a radio frame used for MBMS services. Reason being, 6 bit long bitmap is used to represent sf-AllocInfo-r9.